Extração sólido - líquido com purificação em baixa temperatura: uma técnica eficiente para a extração de dez organoclorados em lodo de esgoto

Abstract

The organochlorine are compounds bioaccumulate and with high toxicity. Despite they have their use banned due to the discovery of their environmental impacts, traces of such compounds can be found in various environmental matrices, among them, the sewage sludge. From the various forms of final disposition given to sewage sludge, the use in agriculture as conditioner soil or as fertilizer has gained prominence, however is necessary the quantification of organic contaminants likely to be found in its composition to eliminate the risk of environmental contamination from this activity. The present research aimed at the optimization and validation of solid-liquid extraction technique with purification at low temperature (SLELTP), to quantification the ten organochlorines in sewage sludge samples by gas chromatography coupled to mass spectrometry (GC-MS). The use of the liner without glass wool increased the intensity of the chromatographic signals of the organochlorines from 9 to 120 times, in addition to detection of the END. The C18 was the more efficient absorber in removing the interfering. In the study of levels to time of fortification of the samples prior to extraction, no significant differences were observed after six hours. Therefore it was selected the minimum time of six hours to the fortification. The selectivity parameters, accuracy and precision were met for all organochlorine. It was observed linearity in the concentration range worked only for ADL and END. The matrix effect was significant only for LND, HCB and HPT. The quantification limits were below the MRL of the EPA.